S-Scheme Nanometer-Sized Bi3NbO7/Bi2O2CO3 Heterojunction Photocatalysts for Efficient Pollutant Degradation

Abstract

Bi₃NbO₇(abbreviated BNO) exhibits favorable visible light responsiveness and chemical stability as a photocatalyst, which could be utilized for the purification of aqueous environments. However, the high photogenerated carrier complexation rate severely restricts the photocatalytic reaction. In this work, the one-pot solvent method was used to improve the photocatalytic ability by preparing S-scheme heterojunction composite photocatalysts by adding urea. The characteristic lamellar structure of Bi₂O₂CO₃(abbreviated BOC) can increase the specific surface area and provide more active sites for the photoreaction. The construction of the S-scheme heterojunction could promote effective charge transfer and consume the unnecessary electrons and holes; meanwhile, the whole system is maintained at a high redox level so as to oxidize and decompose the pollutants. The experimental results showed that nanometer-sized 1.2 Bi₃NbO₇/Bi₂O₂CO₃(abbreviated 1.2BNO/BOC) possesses good degradation effects for the simulated pollutants, the degradation efficiency is significantly improved compared with pure BNO, and the photocatalyst exhibits good cyclic stability.